Data traffic, scheduling and lost capacity in UMTS downlink radio interface

Typical UMTS radio network capacity models yield inaccurate and too optimistic estimations in case of real, dynamic scenarios. The reason for this is that the models assume that all terminals are allocated with optimal resources. In reality this does not hold and due to the imprecision some resources are wasted resulting in lower effective capacity. In this paper, we analyze how the dynamic processes in the radio interface affect the down link capacity of the UMTS system. We also show that the lost capacity can be quite easily controlled if a proper scheduling-based resource management technique is used. The results were obtained from system-level simulations of the downlink data and voice services.